Fibre-optic distributed acoustic sensing can detect acoustic events in surrounding regions along an optical fibre. An acoustic event can be caused by incidents such as underground digging near a gas pipe, water pipe or a power cable, or pedestrian and road traffic activities. Different types of incidents may cause different acoustic signatures in the acoustic event. Monitoring of acoustic events therefore allows for alerts to be generated for the prevention or identification of these incidents, or for tracking of road users in the case of pedestrian and road traffic.
The method of deploying a dedicated optical fibre for distributed acoustic sensing may make sense from a design perspective, such that the fibre optic conditions and parameters (e.g. spatial uniformity along the optical fibre, trench depths, and levels of acoustic attenuation) are known or well-controlled upon installation. However, the installation of a dedicated optical fibre for distributed acoustic sensing can be expensive and disruptive, particularly in and around an urban centre.
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